<template>
  <div class="subject">
    <span>{{num1}}</span>
    <span>+</span>
    <span>{{num2}}</span>
    <span>=</span>
    <input type="number" v-model.number="res" :disabled="isclick"/>
    <button :disabled="isclick" @click="submit">提交</button>
  </div>
</template>

<script>
export default {
    props:['index'],
    data(){
        return {
            num1:Math.floor(Math.random()*20),
            num2:Math.floor(Math.random()*20),
            isclick:false,
            res:'',
        }
    },
    methods:{
        submit(){
            this.isclick=true
            let resultStr=this.num1+this.num2==this.res?'正确':'错误'
            this.$emit('result',resultStr,this.index)
        }
    }
};
</script>

<style scoped>
.subject {
  margin: 5px;
  padding: 5px;
  font-size: 20px;
}
.subject span {
  display: inline-block;
  text-align: center;
  width: 20px;
}
.subject input {
  width: 50px;
  height: 20px;
}
</style>